Effects of Noise Exposure Across the Lifespan on Balance and Stability in Older Adults

一生中噪声暴露对老年人平衡和稳定性的影响

• 批准号: 10670349
• 负责人: Natela M. Shanidze
• 金额: $ 56.03万
• 依托单位: VETERANS EDUCATION AND RESEARCH ASSOCIATION OF MICHIGAN
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-30 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10670349
• 关键词: Acceleration; Accidents; Acoustics; Address; Adult; Age; Aging; Anatomy; Animal Experimentation; Animal Model; Animals; Basic Science; Cells; Cessation of life; Characteristics; Clinic; Clinical; Cochlea; Compensation; Control Groups; Detection; Diagnosis; Disease; Dose; Elderly; Environment; Epithelium; Equilibrium; Evaluation; Exhibits; Exposure to; Force of Gravity; Frequencies; Functional disorder; Genetic; Goals; Head; Head Movements; Hearing; Human; Impairment; Individual; Injury; Investigation; Labyrinth; Life; Link; Longevity; Maintenance; Measures; Methods; Modeling; Morphology; Motion; Motor; Musculoskeletal Equilibrium; Neurons; Noise; Noise-Induced Hearing Loss; Organ; Participant; Performance; Physical shape; Physiological; Planet Earth; Play; Population; Posture; Predisposition; Prevention; Proprioception; Psychophysics; Rattus; Recording of previous events; Reflex action; Rehabilitation therapy; Risk; Risk Factors; Rodent; Role; Rotation; Secondary to; Semicircular canal structure; Sensory; Source; Spinal Cord; Structure; Symptoms; Synapses; System; Testing; Training; Translations; Variant; Vestibular Nerve; Vestibular loss; Vision; Walking; age group; age related; aging population; body position; clinical application; cohort; comparison control; cost; disability; experimental study; fall risk; falls; functional improvement; human old age (65+); improved; insight; interdisciplinary approach; middle age; motor impairment; neglect; noise exposure; otoconia; posture instability; pressure; public health relevance; response; secondary analysis; senescence; sound; treatment strategy; vestibular reflex; vestibulo-ocular reflex

Abstract Loss of stability and falls is a major risk factor for injury and death in older adults. Previously overlooked, lifetime noise exposure has been shown to cause damage to the vestibular periphery; although, animal models and human studies that can provide a mechanistic basis connecting noise-induced vestibular dysfunction and age-related fall risk are limited. The vestibular system plays a critical role in detection of head movements and orientation with respect to gravity and is essential for normal vision and postural control. Due to their anatomical proximity to the cochlea, the otolith organs are exposed to sound pressure and are at risk for noise overstimulation, which may contribute to vestibular dysfunction. However, damage may not be limited to the otolith organs. Recent studies have linked noise overstimulation to decreased vestibular nerve activity and loss of a specialized class of irregularly firing vestibular afferents which exhibit enhanced sensitivity to acceleration. It is likely that these afferents play an important role initiating postural compensation for abrupt changes in head or body position due to their physiological characteristics and their projection to secondary vestibular neurons that project to the spinal cord. Therefore, the effects of noise may accelerate disability associated with natural aging. The goal of this proposal is to characterize vestibular loss associated with natural aging and how it is compounded by cumulative noise exposures throughout one’s life. Thus, we will systematically investigate the effects of noise exposure across the lifespan on otolith and canal structure and function (Aim 1), specifically address the extent of irregular afferent damage and its functional consequences (Aim 2), and asses changes in posture, mobility and balance with noise exposure (Aim 3). Changes in sensory cell synapses will be correlated with vestibular reflex impairment and fall risk associated with postural instability and loss of balance. To improve our understanding of how these changes occur over the lifetime, we will assess anatomical and functional changes in early-, middle-, and late-adulthood. Further, functional experiments will be done in parallel in rats and human participants for maximal translation of our results to the clinic. Individually, both animal and rodent studies have proven invaluable to our understanding of the effects of noise exposure on vestibular function. However, both have limitations that can be best addressed with a set of complimentary studies in the two systems. This proposal describes a comprehensive, multidisciplinary approach that strives to evaluate the underlying mechanisms in increased falls and fall risk due to a history of noise exposure in older adults. The susceptibility of these individuals to potentially fatal falls underscores the need for a systematic approach, that can eventually result in improved training and rehabilitation methods to be used with this population.

抽象的 失去稳定性和跌倒是老年人受伤和死亡的主要风险因素。之前被忽视的， 事实证明，终生接触噪音会对前庭周边造成损害；虽然，动物模型 和人类研究可以提供连接噪声引起的前庭功能障碍和 与年龄相关的跌倒风险有限。前庭系统在检测头部运动和 相对于重力的定向对于正常视力和姿势控制至关重要。由于他们的 耳石器官在解剖学上接近耳蜗，暴露于声压下，存在噪音风险 过度刺激，可能导致前庭功能障碍。然而，损害可能不仅限于 耳石器官。最近的研究表明噪音过度刺激与前庭神经活动减少和丧失有关 一类特殊的不规则发射的前庭传入神经，对加速度表现出增强的敏感性。 这些传入神经可能在启动姿势补偿以应对身体突然变化方面发挥着重要作用。 头部或身体位置取决于其生理特征及其对次级前庭的投射 投射到脊髓的神经元。因此，噪音的影响可能会加速与以下疾病相关的残疾： 自然老化。该提案的目标是描述与自然衰老相关的前庭丧失的特征以及如何 人一生中累积的噪音暴露会加剧这种情况。因此，我们将系统地研究 整个生命周期中噪声暴露对耳石和耳道结构和功能的影响（目标 1）， 具体解决不规则传入损伤的程度及其功能后果（目标 2），并评估 接触噪音会导致姿势、活动能力和平衡发生变化（目标 3）。感觉细胞突触的变化将 与前庭反射损伤以及与姿势不稳定和失去知觉相关的跌倒风险相关 平衡。为了加深我们对这些变化在一生中如何发生的理解，我们将评估 成年早期、中期和晚期的解剖和功能变化。此外，功能实验将 在大鼠和人类参与者中并行进行，以最大限度地将我们的结果转化为临床。 就个体而言，动物和啮齿动物的研究已被证明对于我们了解噪音的影响具有无价的价值 暴露于前庭功能。然而，两者都有局限性，最好通过一组解决方案来解决 两个系统的互补研究。该提案描述了一个全面的、多学科的 该方法致力于评估由于历史原因导致跌倒和跌倒风险增加的潜在机制 老年人的噪音暴露。这些人对可能致命的跌倒的易感性强调了 需要一种系统的方法，最终可以改进培训和康复方法 与该人群一起使用。